Design Diary — Flatten

If you’re looking for how Flatten works, check this article.

How it all started

In Digimon World, you could inflict an LCD status effect on an enemy Digimon called “Flat”. It reduced their 3D model to a DOT sprite like in the v-pets and caused them to use a weak attack. It seems pretty appropriate to include for any 3D Digimon game that wants to include DOT sprites as with set Bit Depth. At the time, I already had this mechanic planned but no theming. So reducing the opponent’s dimensions one by one until they pop out of existence made a lot of sense. Originally, the balance was centered around having to obtain 4 instances of flatten. This didn’t test well. It took far too long to 4-hit-KO even when it can pierce evolutions. The next step was to tweak that number until it felt right in many many games. There was one point where I was torn between requiring 3 flattens and a regular damage hit versus 4 flattens and I ended up just including both due to how supports could be used to add more flats. The 3 flats with damage requirement was slightly too powerful while 4 as a fixed amount was way too slow without a constant supply of support-based flatten.

The case of 3+Damage was easy to fix: simply turn off the ability to KO from the damage unless that player attacked first. Being able to guarantee a 3+Damage flat on second attack meant the opponent was doomed and you could effectively play a support or two and guarantee a win without interacting much. That’s the kind of thing I hate most in games unless the opponent was already at an advantage to start with. They shouldn’t still guarantee that KO if I have the advantage! But of course, that weakened flatten in so many cases where you happened to start the rhythm of adding flats such that you get second attack on that damage turn. In the end, the perfect solution was to allow both situations. If you ended up giving 3 flattens and have the second attack, now is the time to try and get that final flatten by adding in a support.

Small note: Because I know someone will ask, the flatten happens after damage is dealt. So if you have the cross ability at the start of this post, you would deal the damage first then flatten after. Meaning you can’t go from the opponent having 2 flats and simply hit them with your cross for a win!


For some reason, at the last minute I made a huge mistake and changed the number of flats required to 3 or 2+damage as was the final rule. I had been very worried about the balance of such a mechanic for some time and flip-flopped many times during development. But I think it could also be because a playtester came across a fast-evolving deck they absolutely couldn’t beat with the requirements and always lacked enough flats to get any KOs before its actual damage would’ve caused the KOs. They tracked what would’ve happened if they supported with Power boosting and used deadly attacks instead of their special but weak flatten attacks. This was a bad move on my part because it was close to release and made flat a bit too fast for some matchups. This is a very hard mechanic to balance since HP is a variable factor that makes some Digimon harder to KO than others. Flatten is the great equalizer. If your opponent is a huge tank, flatten is great. If they’re a tiny flea, flatten sucks compared to damage. The thing is, your card actually has both. Meaning you can always use whichever is most advantageous! But this person was maybe approaching it in the wrong way. I was later able to test the same matchup (and many similar ones) by simply pivoting to damage when necessary. I found two things wrong with the original test report: you can’t always just pivot to your deadly attack and that means flatten attacks had low risk with high reward (so the “if I used damage” tracking wasn’t accurate); and you can sometimes pivot to deadly attacks which meant getting more KOs (which means they should’ve just done it). It does suck to lose your flat progress during the game by switching to damage. But a KO is a KO. You take it if you can.

How do we stop this crazy train?

After the last minute change, I did at least add a rule where you could remove flats from your Digimon by evolving at a higher cost. This worked well in some late testing and may have been the only mitigating factor that stopped the launch from being awful. But two radical wrong moves do not perfectly cancel out to a right move. I just got lucky this time. The big problem was it broke the DP tuning in every deck it faced. Most players just evolved by DP at the time and largely ignored Evolution cards (my fault—the evolve phase was complicated and those cards were sometimes underpowered). But I do consider this an overall net positive for me as a designer because I was able to quickly find the stress points in the game where it breaks down. This was never meant to be a game so heavily reliant on perfect DP tuning. It’s just one mechanic in a field of so many. I saw why it was breaking down and that gave me insight into how evo-boxes were overused and how the DP cost reduction bonus was also over-used. Once players had to add that reduced 10 DP cost back in, decks essentially evolved at the speed they were meant to without evo-bonuses. This made games a lot closer and reduced snowballing significantly…except versus flatten decks. So now, my goal is to make cards and erratas that do something other than pure DP cost bonuses and make flatten a bit slower as was originally intended. This game isn’t intended to be super fast, flashy, and have tons of effects flying around everywhere!

Digimon Battle Evolution is a game where the most common number of powerful effects you get per turn is 1. There are ways to extend it such as with evo-bonuses, Evolve phase card play, and Any phase card play, but the absolute most common and intended experience is one major effect per turn. In TCGs with alternate win conditions, you usually suffer a failure if any of the following happen: The opponent plays a bunch of cards that tilt the game’s favor away from you; you brick combining your cards for the alt-win due to chance; or it was designed poorly. This makes alternate win conditions in most games either overpowered (when those factors are eliminated) or unreliable.

For this reason and many others, I tend to shy away from creating game wins that weren’t originally intended. Games tend to systemically fail if you don’t go with the flow. But in DBE, Flatten doesn’t actually provide an alternative win, just a new method to the existing win condition. It’s like if HP didn’t reset on evolution. If that were the case, you’d need some complicated process to take the difference between your old printed HP and new printed HP and add that to your current HP. This could obviously be very annoying to figure out in-game. Plus it could cause very swingy games as players get hammered. That might lead to lots of decks being played that primarily stall. Stalling is not fun. Just as alt-win conditions are often not fun to have played at you, too much stalling also means you don’t get to play. For every “take that!” mechanic in these sorts of games, there has to be some negotiating factor on behalf of the designer to make sure the game stays fun for both players. Flatten is a mechanic that can pierce through a stall deck because screw those things.

Tedious tracking

So it feels good now (as it did up to about a month before release) but the way you actually track flats in-game…ugh. You used to pull a blind card from the top of your deck and that was your flat token. Neither player could look at it. Why did I do this? Because I was desperately trying to avoid adding auxiliary tracking tokens into the game. I like when a game is simple to carry around and repurposes its cards for many uses. DBE already does this with Digimon cards: They have stats for battle, evo-bonuses for small effects, supports for big effects, and +P to help evolution. I try to put as much of the games work on the card itself so players can get to the good stuff. But flat wasn’t built into the game at first, so I didn’t have an intuitive way to track it. That irrational hatred of little coins or tokens to track flatten became an annoyance to decks that recycle, recode, or otherwise mess with the top of their deck. And it essentially made flatten incompatible with corrupt as a mechanic and half the card “Lucky Banquet”. Plus, you’d go to take a card from your deck with some search effect and figure out a key component to win was stuck face-down as a flat token.

Due to the subtle decision trees players follow in the game to mulligan, it actually meant that flatten would hit Aces, Firewalls, Partners, and other power cards much more often than if by pure chance. You typically won’t mulligan your hand if those power cards are present and typically will if in a bind and they’re not present. This means your very decision structure sort-of filters the good stuff to the top faster. All a flatten player has to do is hit with flatten during the midgame. This was already a concept used in decks that trash cards but at least that mechanic was designed to achieve that card denial. And it was soft-denial in that there are effects to take stuff out of the trash. In the end, I had to admit I was wrong and just require players to bring flat tokens to each game. It’s not a big deal anyway since flatten is not an effect you throw into any old deck (again, similar to trashing).


LCD-screen effect applied to a Tyrannomon sprite.

Click here to also download a printable TIF at 300 DPI, ~1 inch.

The end of the beginning

Now the only hard parts left are how much to support the damn mechanic! When you introduce a new mechanic into a game, it’s best to try and populate it heavily but also not overwhelm one set of cards with it, or else everything will feel lopsided. Usually, the solution is a big-ish set release with about 20% of your cards being peppered with it uniformly. Since Bit Depth was a big Marine release, it was the obvious primary choice to kickstart the population of the effect—incidentally, BIT has 70 cards with 14 originally printed with flatten, exactly 20%. Nature was originally my second choice since it too was very prominent but I backtracked this immediately during the first round of card tests due to interference with Nature’s normal mechanics—that “master plan” they do with all of the tactical conditions. I ruled Dragon out because smashing things is their deal, not flattening and a good half of the BIT Dragons were also Nature. Jungle was a terrible fit since you’d get so powerful from fast evolutions that you would prefer defense rather than a slower offensive mechanic. It later became the counter to flatten itself once DP-healing was added—making Jungle even worse since it would be its own mirror match counter. Or maybe that’s better. I don’t really know. Enigma is oversaturated with mechanics (especially in BIT which added Static) and should never be allowed to KO that easily with its deliberately weak Level Cs. In the end, Nightmare was the better secondary fit due to its heavy focus on disruption effects and game flow control.

But then more problems. Always more problems. I was designing something that literally flattened the game’s flow after all. A game primarily designed to have variable flow as a primary mechanic, to reverse snowballing and allow players themselves to evolve during the fight! Like if DBE wasn’t free, all that weaving and changing would be the selling point. So the new problem is that I have my 20% (spread among Cross abilities and Support effects) but now every card with a flatten effect is only good in a flatten deck. When I designed “Shatter”, it had the same problem which I fixed by giving it the power reduction effect with the attachment-breaking. Flatten is already too complicated for heaping such extra garbage onto the pile and too bespoke to leave as it is. The solution was actually pretty easy. When you playtest a rough mechanic, always leave multiple alternative rules open to yourself and see which ones you use the most often. Before, I did that with the number of flats required to KO in order to find the right balance. Doing it again, I could just change the Supports into “OR” with some other useful effect! Costing that properly was pretty easy too. It’s just the same as any other OR.

Cross specials had to be changed in a slightly more complicated way. The first thing was removing Flat from ALL non-Marine cross attacks except a couple which I will explain. Since flatten isn’t very good on its own, it needs a huge body to support it in the form of Level U or M—and Level M prefers to guard its precious 2 KO points rather than spend all day trying to get a KO in the slowest way possible. Personally, I also didn’t like how it removed the tense and interesting interactions with trying to decide between a deadly but risky Circle attack and a boring but reliable Triangle attack. You take all the guesswork out with that super-hard to punish but weak special Cross. This can be fine at lower levels, but M? That’s the end of the line. Literally, in Japanese “Kyuukyoku” or upper limit; zenith; ultimate. There’s nowhere left to look forward to, so it’s time to get down to business and really lay on the hurt. Flatten is primarily balanced for the Level C portion of the game and secondarily for fighting against Level U+ or between two unevenly matched Level Us. Since Marine was so populous, it could stay on their attacks as long as their HP was very high (which it is), since that wouldn’t detract too much if they were simply placed into a non-flatten Marine deck. That one card could still KO through Flatten just fine due to its heavy endurance.

As for the other oddball cases where something isn’t Marine but has the Flatten…remember how its the great equalizer? Well if you’re Level R, it’s similar to getting x3 VS. This means most Level Rs with x3 VS in either Marine or Nightmare could be substituted for a type-based Flatten. There’s tradeoffs. If you wouldn’t stay on the Level R and stick out that full KO, you pretty much lose all your progress without any support. But you do have the opportunity to stick it out with some protection due to how the damage persists after evolution. So x3 VS is preferred against a slower deck since the damage sticks after you evolve. But Flatten is preferred against the faster decks (funny enough) since you have a chance to keep the Flat point or scare the opponent into removing it at a cost. This makes Tapirmon potentially very bad in a deck without protection but potentially good too if you can pull off a bluff that you’re really going for Flatten KOs. Of course, x3 VS is in a similar boat to Flatten already, given that both are conditional on some opposing type or having extra support to finish the job. Because of this, it can be costed similarly but with great caution. The other example was Minotaurmon but it’s special. Firstly, Minotaurmon exists in 3 types so future flatten support scales very well with it. Secondly, it’s an unconditional Flat, so it’s an all-in-one solution. There’s never a dead case for the Flat that wouldn’t be universal to all flats.

So what’s the solution going forward? I initially wanted to sprinkle Flat support into every future set but that’s proving harder than I anticipated. Most sets just don’t have such lopsided release support for one type and are large enough. It doesn’t fit well into auxiliary sets because they’re small. Except for Nightmare or Marine. Nightmare still needs more but more Marine just compounds the problem of lopsided flatten. There are very few large-ish sets planned and those don’t have lopsided types, so I’d have to sprinkle the Flatten in uniformly, hoping to make future support. That makes those cards feel bad in the meantime. It may be that Marine and Nightmare get future Flatten attack abilities but everyone else gets Supports with “OR” clauses. Whatever the case may be, I’m looking forward to solving this puzzle as with so many others during my time designing Digimon Battle Evolution.

The final thing I should say is I hope people have fun with flatten. I saw several players enjoying it even with the rough release. Hopefully that experience is smoother now and can be expanded in the future.

Alice White

Alice is the webmaster of VMundi, author, editor, mathematician, and autodidact. She has over 9 years of publishing experience writing articles for various self-run sites. Her interests include game design, economics, Game Theory, graphical design, and mathematics.

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